No the A3 itself doesn't exist, as per my original comments on the Release notes. The L86A2 was modified to bring it inline with the other RIS varients of the L86.
Changed to bin the plastic furniture, add on RIS Weaver rails. New more modern Optics. etc. So can still be called "L86-A2" just with the "RIS" Moniker.

(note we're discussing the L86 not the L85)
Cheers for the reference info on the NEW L85-A3 prototype Jam... As that's cracking brand new I've moved it to our reference topic on the Modding weapons thread. Good find BTW. Lets keep this clear for Bugs on the current release.